A look at weather extremes and the big-picture climate connections.

Colorado Wildfires Explained in One Chart

On Wednesday, more than a dozen wildfires were burning in Colorado, including massive conflagrations that are threatening two of the state's largest cities — Colorado Springs and Boulder. The fires are the result of a rare mix of ingredients: drought, unprecedented heat, lightning strikes from dry thunderstorms, as well as changing forestry practices and exurban sprawl that have helped prime forests for large fires. 

This one chart, more than any other graphic that I've yet come across, explains one of the main reasons why Colorado is so combustible right now. It shows snowpack data from a network of monitoring sites called SNOTEL, as measured in snow water equivalent. In other words, it shows how much water is (or was) present in the Colorado snowpack.

Chart of the Colorado snowpack during the past four years, showing the thin snowpack and early melt in 2011-12. Click on the image for a larger version. Credit: Natural Resources Conservation Service. 

The lines trace the buildup and melt of the Rocky Mountain State's snowpack during the past four years, and they clearly show that the 2012 winter season delivered anemic snow cover to Colorado. Not only that, but the snow that did fall melted extremely early, allowing soils to dry. Studies have shown that years with early snowmelt tend to have more severe wildfire seasons. This contrasts with the 2010-2011 winter season, which featured plentiful snowfall that lasted into early July. 


Best & Latest Info to Track Wildfires in Colorado

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Heat Wave Spawns Deadly Severe Thunderstorms

According to the chart, produced by the Natural Resources Conservation Service, the 2011-12 winter snowpack peaked on March 6, 2012, more than a month earlier than average, and the meltout date of June 4 came well before the median meltout date, which is June 25. And at its peak, the snow cover contained much less water than normal.

The back-to-back combination of the deep snowpack in 2010-11, which encouraged spring plant growth, and the lack of snow this past winter has led to abundant brush that has dried and ready to burn.

As the snowpack began melting in March, veteran environmental journalist Tom Yulsman wrote : "Like a spring avalanche, snowpack in Colorado has plunged off a precipice." Yulsman, quoting officials, warned of severe drought conditions to come, along with a potentially fierce wildfire season.

Unfortunately, that is now playing out.

« Extreme Planet


By Kat M (Burlington, VT)
on June 27th, 2012

Let’s not forget the role that pine beetles have played thanks to climate change. Due to climate change, pine beetles are more active. Higher temps speed up their reproductive cycle and reduce the number killed by lower temps. Drought weakens trees and makes them more susceptible to attack. This combination transforms acres upon acres of forest into kindling.

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By Andrew
on June 27th, 2012

@Kat - very true, although I’m not sure about the role of pine beetles in these specific fires. We’re studying this issue, and will have more on it soon, so stay tuned…

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By Ben Simpson (Custer, SD)
on June 27th, 2012

@Kat, that seems to be true to my subjective experience in the Black Hills of SD. Whole hillsides are dead and fall if everywehere.

@Andrew, is there a larger data set in which to look at of snowpack? And could the change be correlated with warming?

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By Andrew (Brooklyn, NY)
on June 28th, 2012

@Ben - Here is the broader SNOTEL data: http://www.wcc.nrcs.usda.gov/snow/ . As far as correlating that with warming, there are many studies showing that snowmelt tends to come earlier in the spring now in some parts of the West, and that this trend is associated with the severity of the wildfire season. But natural climate variability, particularly El Nino/La Nina, has the biggest influence on year-to-year snowfall variability.

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By Renea Ellyson (Amarillo, Texas 79106)
on June 24th, 2013

We have reservations for June 28 thru July 2 at a cabin near the Platoro Resovoir in Colorado to hopefully do some trout fishing at Mix Lake. What is the status of the wild fires around that area and are we only going to have poor scenery of burned forests during our trip from Amarillo, TX to that area?  Can you recommend a good route to get there for the best scenery and if there is eminent danger from the current fires in that area?

My thoughts and prayers go out to all of the people affected by the fires. I wish there was something that more I could do to help, but my prayers are the best I can offer to them at this time.

Thank you for your earliest response.

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By Lindsay Harmon
on June 25th, 2013

Hi Renea.

A great way to track the status and location of the fires in Colorado is to use our interactive wildfire tracker, which is updated daily.


Simply hover over a given fire to see its name and zoom in to see the outline of the area that’s burning. If you click within the area, a window pops up showing the fire’s size in acres, the amount by which the perimeter has grown or shrunk over the past 24 hours, the fraction of the fire that has been contained and other data. There’s also a link to an even more detailed report.

As for recommended route, we are based in Princeton, NJ so are not experts in that area and are unable to advise. Thanks so much for reaching out and travel safe!

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By Téo Corthout (belgium)
on July 20th, 2013

As a paleo climate scientist I have basic understandings of climate dynamics and carbon dynamics.
I developed my own climate matrix (state by state) that dates back hunderds of thousands of years.
What we see in the united states is a phenomena I call a QUADRATIC climate (which is unique on the planet).

Precipitation per state and snow reduction for the higher areas for the next centuries is well known today. 

Who is reforesting the black spots? Is there any policy for fire resisting trees and fire corridors? 
Enjoy your forest!

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